Organotin trimercaptides



Uniwd States Patent 2,731,482 ORGANOTINTRIMERCAPTDES Eugene P. Stet], Churchill Valley, Pa., and Chris E. Best, Franklin Township, Summit County, Ohio, assignors to TheFirestone The 85, Rubber Company, Akron, Ohio,

Incorporation of Ohio 1 No Drawing. Application October 5, 1950,

a Serial No. 188,653 1 The compounds of this invention are embraced by the formula l te (I; in whichformula 1 R1, independently in each occurrence, represents an or} ganic radical consistingof from 1 to 22 carbonatoms, hydrogen, carbon-carbon single bonds, carbon-hydrogen bonds, (optionally) aromatic ring carboncarbon double bonds and (also optionally) a maximum total of four innocuous structures such as carbon-carbon.

triple bonds, aliphatic carbon-carbon double bonds, ether, linkages, thioether linkages, carboxylio ester groups bonded to carbon atoms,fiuorine atoms linked to carbon, and halogen atoms bonded to aromatic ring groups bonded to carbon, sulfhydryl groups bonded to,

' carb omether linkages, thioether linkages, carboxylic ester groupsbonded to carbon atoms, carboxylic amide gr'ou'ps bonded to carbon atoms, fluorine atoms bonded 'to carbon atoms, halogen atoms bonded to aromatic ring carbon atoms and groups of the formula 1 under the same notation.

In the above and all following formulae, theat oms in the groups R1 and Rzattached to the sulfur and tin atoms must always be carbon atoms. It will also be understood that the. innocuous groups mentioned as optional constitu entsof the radicals R or.Rz,need not all beidentical ,inwany givenradical R1 or R2,, but their totalnumber, enumerated without distinction as to kind of innocuous 2,731,482 Patented Jan. 17, 1956 group, must not exceed four in any given radical R1 or Rs.

r so

The compounds may conveniently be prepared by react ing mercaptans of the formula 1 PS-n (II) with organostannic acids of the formula II R1-Sn-0H (111) all under the notation given in convention with Formula I above. Water is eliminated, with formation of the desired compounds (I).

Reference is made to the copending application of Stefl and Best Ser. No. 188,654, which relates to the stabilization of vinyl chloride resins with organotin trimercaptides.

THE SUBSTITUENTS R1 AND R2 practice, a range of from 1 to 22 carbon atoms in each,

of the radicals R1 and R: will cover the field of radicals which will be conveniently available and not too large to be readily reactable in the synthesis of the compounds in of this invention. The radicalsR1 and R2 may be, and from the standpoint of ready procurement and avoidance of complications in synthesis preferably are, simple monovalent hydrocarbon radicals containing only single bonds between the carbon atoms or aromatic ring double bonds between the carbon atoms (practically, there will be a maximum limit of 11 such double bonds in any radical), for instance alkyl, cycloalkyl, aryl, aralkyl, alkaryl and like monovalent hydrocarbon radicals containing from 1. to 22 carbon atoms. Likewise these radicals, in addition to simplehydrocarbon structure, may contain various other groupings which aresufliciently low in number, and of sufiiciently non-reactive character, as not to interfere with the synthesis of the compounds of this invention. Structures which have been found innocuous and noninterfering in either of the radicals R1 and R2 are, inter alia,aliphatic ethylenic linkages (as distinguished from the unsaturated bonds in aromatic rings, which may be present in numbers limited only by. the size of the radical R1 or R2 in question), acetylenic linkages, ether linkages, thioether linkages, carboxylic ester linkages, fluorine atoms bonded to carbon atoms, and halogen atoms bonded carboxylic amide groups. Likewise, the radical R2 may be linked through sulfur atoms to more than one organicsiibstituted tin atom, in which casefthe radical R1 of Formula I will contain a further group of the formula r 1 3 (I-A) in addition to the tin atom grouping of this character already shown in Formula I. Itwill be understood that I p pz mp n bu may. rz'm the groups'Rz in the Formula I-A admit of expansion, so as to include networkpolymeric materiaismfthe-type I i R'frS-SD-Jh;

ii p

In' generaljit'has been'found. thatfrom 1 to time,

" nno uous: ps e i th bo v e; p e entea offthejradicals R1 andfR'i in the formulae above.

7 Offallf'the radicals coming within theambitofRi and? R2 as above defined;thesirnplehydroc'arbon. radicals ,con: taining not; more than aj combined total of "four, nonaromatic ethylenic linkages; andace tylenic linkages will" be. p referred," "as the starting materials for these compounds willfbe mostrea'dily accessible, andless complication will 1 b'eencounterediin thesynthetic steps leading to. the compoundsof this invention. I

.Itf has also "been observed in .the practice of j this .invem tion that' te rtiary'mercaptans react less readily and'completely than do other rner'captans. in the formation 'ofthe compounding; of this invention. 7 The resultant; mercap v.

' tides therefore constitute a.le sspreferredclass ofj'com,

pounds'in accordance with' this invention, ,whilei nevertlie:v less remainingyithin the ambit thereof.

Itisgto be understoom' of course, thatthe radi'calsRr any. a s ar not; d n l. h a h. 'cebiut' ay be. diiferentgra dicalseach i dividually comingund'er, the.

,d fin t nio i l h. a l's 'seiv n a ov t nd l ata-p nw ration" in: accordan w th his inv nt on. need; not. at

mnd fit e en a .F muil bovesu h asrw u result; for instance when starting materials I were used'tl e of 'compoundk 39 I 4,, wherein R1 and R2 are as defined above in connection with Formula'I': Itwill' be understood that theForrnula III for the organostannic acid is somewhat idealized, since these compounds occur largely as pyro acids of varying degrees and complexity of condensation; however, the pyro acids mercaptolizefairly readily under the conditions of thereaction, .whichtherefore proceeds-effectively as shown. In some preparations of organostannic acid,

. several positions on;the;-.tin' atom-tin variouscomplexions.

and""R2 in their several; occurrences needjj not be, andjin.

which would supply mixtures ofi'radicalsgfor'instance;

starting materials derived from natural sourcesor from petroleumfractions.

' i .ml ilw lqiil. 1

A convenient synthesis fonthe compounds of this invention involves the reaction the;- degreetof. condensation may .be so; high:;. as totresulfi.

in somewhat reduced yields, and it. will be-preferredi-to employ. acidsof a relatively low degree: of condensation. It is to be understood that in many-cases 'the'three-mercaptan molecules. indicatedrbyi the notation. flees-Ra are identical mercaptan; molecules, assuming that an unmixed mercaptanis supplied to the reaction; if a mixtureof mercaptans'is supplied to'thereaction, these will distribute themselves, in accordance with the reactivities involved,- betweenreactive engagements .in ,whichjhc' mercaptanmolecules reacting with; a .givenorganostannicacid. are all identical; and those in;whi ch the mercapl nmolh cules are not allidentical (e. g. two .alikeyandone, similar, or all three dissimilar) and are arranged at the,

In accordance with the notation above, the radicals R2 may themselves contain -thiol groups, i. e., theamercaptan (II) may have the formula HSRs&-H as Rrisde fined above in connection with Formula IV, in which case a greater or less proportion of the mercaptan (II) will react with two organostannic acid molecules (III) re-resulting in reticulate structures such as indicated by Formula IV. The reaction is readily and simply carried out by mixing the mercaptans (II) together with the organostannic acid (III) and heating the mixturewith stirring at temperatures in the range 40CI-180" CI In most .casesthemercaptans will not bevolatile under. these conditions and. the reaction may beicarriedout inopen vessels;- however,v some ofjthe lower mercaptans may have appreciable, or even superatmosphericfvapor pressure'sat these; temperatures, in: which. case the. reaction may, be carried, outinclosed. vessels with provisionforreflux and,

if.' necessary. to confine the reactants, maintenance-of superatmospheric pressure. The; reactionis more readily controlled; if, not; all the organostannic. acid is,v added. at the outset but rather, is. added in. increments astheflreaction proceeds. The reactants will be used insubstantially equivalent, proportions, as, the reaction is. substantially quantitative; however to the extent. that .theproportionationmay beinaccurate, the mercap tan should be'usedlin gQOrLyield,almostjnstantly, upon mixing, and, going; substantially to, completion 1 in Q the course of. an .hour, or, so. The reaction maybe carried out in the absence of a solvent, since the mercaptan employed will usually be a liquid, or at least fusible at the temperature of reaction. Alternatively, a suitable'non-reactive solvent may be employed, such as hydrocarbon solvents on the order of petroleum ether, benzene, toljuene, xylene orthe like, or chlorinated solvents such as carbon tetrachloride, trichlo roethylene, tetrachloroethylcne, hexachlorobutadiene, and the like. When a solvent is employed;.it-mayt-beievaporated out of the reaction mass to entrain and remove the water-resultingfrorn thereaction: j V

'As noted above'the' radicals-"Kr and'j-Rzare not critical" in;nature;andimaybe-selectedfromawide variety'ofsuU; stitnents examplesoffwhichmreilisted. Ther-r adical's fR'a theamercaptan. or. m mpt s'gsuppliedi tome-reaction; ,whiletheradicals; Rraretliose-attached'f to organostannie' acid supplied" to the -p-Trifiuoromethyl thiophenol I I reaction. Given herewith are selected lists of mercaptans and organostannic acids conforming to the requirements of the radicals R1 and R2 given above. Any one of these or similarmercaptans may be reacted with any of these or similar stannones to yield compounds according to this invention. I

Table I.Mercaptans Methyl mercaptan Butyl mercaptan Amyl, mercaptan n-Hexylmercaptan 2-ethyl hexyl mercaptan tt-Octyl mercaptan Decyl mercaptan Dodecyl mercaptan Mixed mercaptans derived from fatty radicals of cocoanut oil or other natural fatty oils Mercaptans from trimerized isopropylene Mercaptans containing the alkyl radicals petroleum fractions Tridecyl mercaptan Oleyl mercaptan Thioabietinol, or other mercaptaus derived from the hydrocarbon residues of naval stores products, tall oil Mercaptans derived by conversion to mercaptansof the alcohols produced by the carbon monoxide-hydrogen synthesis, or the mixed alcohols produced by the oxo process c l Mercaptans produced by reductionof the alkyl sulfonic acids resulting from ultraviolet-sulfuryl chloride treatment of parafiins 2 mercaptoethanol I 2 (2-m ercap toethoxy ethanol 2-ethyl hexyl thioglycolate Z-mercaptoethyl stearate Z-mercaptoethyl stearamide Eicosyl mercaptan Benzyl mercaptan m-, and p-Chlorobenzyl mercaptan 4,4-diphenylether dithiol Thiophenol o, m-, and p-Chlorothiophenol Thio-p-cresol u-Thionaphthol p-Thionaphthol Thiophenethiol Mercaptobenzimidazole Thiosalicylic acid Thiocinnamic acid Z-mercapto methyl benzoate p Bromothiophenol 1 of kerosene Methylstann ic acid Ethylstannic acid I .Butylstannic acid 'a-Naphthyl stannic acid N 2-thienyl stannic acid I U Xenyl stannic acid I Ethoxyethyl stannic acid the mercaptans employed.

6 The compounds prepared in accordance with this in vention are for the most part liquids at ordinary temperatures, although some of "them may be solids. They are useful as intermediates in the production of other compounds, and find particular use as stabilizers in vinyl chloride resins.

EXAMPLE I t t I Gram-mole Mercaptan (per Table III) .3 Organostannic acid (per Table III) .1

A series of monoorganotin trimercaptides was prepared byreacting together, in combination set forth in Table III hereinbelow, .3 gram-mole portions of various mercaptans with .l gram-mole portions of various organostannic acids. In each case the selected mercaptan was placed in an open beaker and heated to 125 C. (In those cases where the mercaptan was volatile, e. g.

butyl mercaptan, the reaction was carried out in a closed filtrate taken as a substantially pure monoorganotin tri inercaptide in which the organic groups directly attached to the tin werethose originally present in the organestannic acid, and the organic groups linked to thetin through the sulfur atoms were those originally present in (In some cases, wherethe productswere highly viscous or solid, the reaction mass I was diluted withpetroleurn ether for the filtration, the

solvent being strippedotf after the filtration.)

The products were then tested as stabilizers in vinyl chloride resins as follows:' (The parts given are by weight.)

Parts Copolymer. of 97% vinyl chloride, 3% vinylidene chloride 100 Di(2-ethyihexyl)phthalate 46 Tricalcium phosphate l Silicate pigment -L V l Stabilizer compound under test 2 A series of compositions was made up in accordance with the foregoing schedule, using as the stabilizer each of the organctin trimercaptides prepared as above de scribed and tabulated below. In each case the listed ingredients, together the compound underte'st, in the proportions indicated in the schedule were thoroughly mixed together and placed on a laboratory 'roll mill at 320 Milling was continued for two minutes, at which time d e gauge was set at .025 inch and'the sheet re moved from the mill and cooled.

l ive one-inch square specimens of each ofthe sheets of each of'the "compositions prepared as above described where hung vertically in a forced-draftoven maintained at 170 C. 1 Specimens ofeach of the compositions were removed after intervals of 15, 30, 60, 90 and 120 minutes of exposure in the oven, and were rated subjectively as to color and extent, of deterioration by the the operator,

which rates are set forth. herewith in Table IILopposite the tabulation oi the preparation of the compoundsQof this invention By way of. contrast, a'comp'osition infip. cordance with,the vabove.forrniila, but omit'tiiiglthe ,stabh lizer, showed marked deterioration after as short a time as 15 minutesin the oven, see the last item in Tablelll.

Table IIL- dmtltutionrotlfroduct-p properties etilfroductl Colonel-.Testflfgecimeu After-.lliruosure-ln merrier-- Groups at Used, Run... tach'ed to Mama (parts by I No:

Sulfur in Point "u "we/ight) Min. Min. Min. M111. Min, I Mercaptan Acid Used. Used Butyl 2.0 oft-white pale straw"..- 1 secmmyll... 2:0: infidel. straw 2 V 25 palestraw... pale strewn. 3

Cocoanut 1.4975 4,

5 2 6: gq d u pale straw l 7' octadecyil'" ofl-whlte.. off-white pale straw 8" v blaek edge. alphapineuoI 1. 5449 straw straw l ;st raw 9,. mercapf l\1othyt1"...-.; taut v I zshydroxy 1.6168 20. (lo faint'strawnfl light straw. light strawm. straw, blaelc L 10; ethyl;' I i edge.

alph'anaph 2.0. .do oft-white straw; straw; F 11; b-oreszlz 2.:0' faint yellow pale straw -do.. light brown. '12 be 2J0. palo'straw light tan. brow-11;. darlnbrown; 13'

eh'lorohenzyli 1 6523 2 0' 'white..'. white bfifiwhiteflv 'pale strawznfl straw, black l4 V 1 spot. dirt rllmnyii- 2.0 iaintyellow... taint yellow... yellow yellow muddy yellow. .7 l5--- i 0- er r-' V I i 3 thloli; Ethyl.-. :C0connut. 2.0 White white .w 16- Butyl 2.0 'oifiwhite off-white light stra 17 Qocounut 2.0. white o.- o ivvhite. 18 t-Docecyl... 2.0 cream pale straw pale straw." v 19 t Bfmyl 'p-Crcsyl- 2.0; white. :ofi-wl1ite straw do; tlightbrownh. 203

, v Methyl-bone stiii resin- :0 light beigc .iight reddish light brown; broivn .,.i vbrown.. 2i

zoate on: prod 1 browm I i no v t ,(locoanutL 1.4920. .211 palestraw.. straw s 22 p-Qresyk. 2:05 straw..- dark brown") 23 gutylqwg stgawfilblack ?;4=. a. .ocoauu, o :w. te, 25 i blaekedges.

1 bCr'esyl; 1.6890 250 black 7 26 Thienyl .Coeoauut 14729. 20 27 Control without stabilizer .y.-. 0' dark brown... 23;

-. Thesezurermixedlattyradicalsyeonsistinglargclyoiluuryl'nnd myristyl, der ved by reduction of the fatty ac ds of eoeoauut'oill i This is the name of the mereapan employed not the group attached to sulfur therein, as set out in the column heading. I

Recrystalllzedfiom-heptene; Analysis in icated 18.93%sulfur as again t a theoretical 19.1 sulfur.

" ring carhon-carbondouble. bonds, andjgup to 4- innocuous structures selected from the gtqup consisting; of. carboncarbon trigle, bonds, aligliatic; carbon-carbon double b'gndsie'tli'er linkages,- ,tbioetlicr linkages; carboxylic, ester,

, 'honde dto carlion fiuorinej; atoms bonde'dflto car- Bon, d; halogen atoms bjonded to; aromaneriiiggcar; lion,--e aich R'1.being linlcedgto the tin'atorn in thc formulae liereinaboveandhereinbelow by'orie of its carbon atoms, and 'R gindbcndcntlydri each occurrence, represents an organic radiealicon'sistirig of'and'f containing from 1 to 22*carlionf atoms; hydrogen; carbon -fcarbon single bonds,

bonds; up =t0= 11 'romaticring carbonr I and from: 0 to 4 innocuous struce from, consisting ot carfion-cerhom aligliatic commu er doublebonds, by; dfoxy gtoups honded tocarbon, sulih-ydrylj groupsbonded to carbon, ether linkages, th'ioethcr' linkages, ear:l

hoxylic ester groups bonded to carbonycarboxylic amide.

groups of the formula 7 under the same notation, each of the radicals R's-being linked to its respective sulfur atom in the formulaeby one of its carbon atoms. V

2. Methyltin trimercaptide. of the mercaptanscontain ing the mixed fatty radicals derived" by ireductiono'fthej. fatty acids of cocoanut oil.

3. Bu'ty1tin trimcrc tide, of thc-mercagtaus containing the mixed fatty radicals derived by reduction of the fatty acids of cocoanut oil.

4. Butyltin tri(p-eresyl) mercaptide; 5. Phenyltin trimercaptideof the mereaptans contain-- ing tl te mixedfatty radicals derived by'reductiomofi the- 1) fatty acids of cocoanut oil. a

6. Z-thienyltin trimerc aptide of the;inercaptans' containing the mixed fatty radicals derived' byreductio'n oh the fatty acids of cocoanut oil.

References"Cited-'in-the file' of'this-z giatent UNITED STATES-Planners; v 2;489,5l8 Burt V Nov.= 194a OTHER REFERENCES; 1 I c. A., vol. 25, page 3340. r I 

1. A COMPOUND OF THE FORMULA 